A relationship between elite athlete and coach is bit like that of a married couple: they have their disagreements but need to trust one another and want the same things out of life. If not, divorce is usually inevitable.

For three years, from 1997, Denise Lewis and Charles van Commenee were the perfect team as Olympic gold beckoned at the Sydney games. But in 2002 it all ended in acrimony. Lewis had a baby girl with her partner, the Belgian sprinter Patrick Stevens, and Van Commenee walked away, claiming that motherhood and world-class athletics do not mix.

Lewis returned to the track last year but under Frank Dick, Britain's former performance director, and controversially Dr Ekkart Arbeit, the architect of East Germany's state-sponsored doping programme.

From the sidelines Van Commenee was dismissive of her fifth place at the world championships in Paris last August as she began the long haul towards Athens. Lewis scored 6,254 points, well below her personal best of 6,831. "It was painful to watch her under-perform the whole summer," he said.

The Dutchman's words clearly had their effect, because Lewis has joined up with him again after dropping Dick and Arbeit. "At a certain point she asked me to take her on," said Van Commenee. "She was persistent, so I felt I had to help someone in need."

Lewis, 31, is now back living in Birmingham, where Van Commenee is based as a technical director for UK Athletics. With the best facilities in the country available at the Alexander Stadium, he supervises her training twice a day, six days a week.

Her progress will be revealed this weekend at the Norwich Union world indoor trials and AAA Championships at the English Institute of Sport in Sheffield, where Lewis competes in the 60m hurdles and shot.

"She has been out of competition for a long time, from 2001 basically, and for her it is a good opportunity to feel what it is to be in the blocks with other girls next to her," said Van Commenee.

"The other reason is that she loves competing; no one starts the sport for reasons of training, but of competition. She is getting better and better. She is probably better than last year, although we have had quite a few setbacks. We are not where we want to be in February."

Her association with Dick and Arbeit did not turn out to be as good as the brochure. "She was behind in every area, almost," said Van Commenee. "Especially the jumps - they need extra attention. She was behind compared to her biggest rivals and behind to her own standards from the past."

Acutely aware of how sensitive the topic remains, Van Commenee will not be drawn publicly on Lewis's relationship with Arbeit nor his comments about how starting a family would damage her athletic ability. "Let us start a new chapter," he said.

One of the important factors that led to Van Commenee linking up with Lewis again is that she had returned to Birmingham, although Stevens still lives in Belgium. "It is also the setting which is very different: she moved house, she is working in different environment. Everything is different, a whole new experience," he said. "It is much harder to defend a title than to win one. She is coping well with fitting everything in.

"Denise is not going to give up her Olympic title just like that. You ask yourself the question when you are training: how far are we behind, what does it take to win?

"There is a big difference to four years ago. At this point then, she was the No2 in the world from the world championships in Seville [in 1999 she won a silver medal there] and she was not too far behind the No1. Now she is 10 miles behind the world No1, No2 and No3, so it is a different perspective. Although she is the defending Olympic champion, I cannot see her as the favourite. It is all about getting in the medal zone rather than going in as one of the favourites to win.

"As a coach, 99.9% of your athletes are not winners; every coach is used to working with athletes of a lower standard. I have coached many athletes who are trying to improve and who are not as good as they used to be.

"Every single day you try to get the best out of the athletes. The standard is lower for her than four years ago, but it does not make the challenge any less and I can guarantee when we are out there, you go into the blocks to win, nothing less."

Lewis is due to compete in her first full seven-event heptathlon of the year in Gotzis, Austria, at the end of May. There she could again meet Sweden's world champion Carolina Kluft, who in Paris became only the third heptathlete to pass 7,000 points. The brilliant youngster looks set to redefine the event, but history is littered with favourites who fail to win Olympic gold.

"I always make this comparison with Jonathan Edwards, who broke the world triple jump record in 1995 and nobody could come close," said Van Commenee.

"A year after he did not win the Olympic title. No one could have predicted that the Olympics in Sydney would be won with 6,500 points. Nine weeks beforehand two athletes scored 6,800. Things can be unpredictable in the heptathlon."